JP2665308B2 - Ghost elimination reference signal having Bessel chirp signal and pseudo-noise sequential signal, and television receiver using the signal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ghost cancellation reference signal (Ghost Cancellation R) used in a television receiver.
eference signal (hereinafter referred to as GCR signal) and this GC
The present invention relates to a television receiver using an R signal.

[0002]

2. Description of the Related Art ATSC (Advanced Television System)
The T-3 subcommittee under the s Committee has a meeting to determine the GCR signal for use in the United States, where the GCR signal contains two signals, the Bessel pulse chirp. GC using GCR signal to be used and pseudo noise sequence
It is compromised on the basis of the R signal. A GCR signal using a Bessel pulse chirp (hereinafter, referred to as a chirp signal) has been proposed by Philips in the United States, and a GCR signal using a pseudo-noise sequential sequence (hereinafter, referred to as a PN sequential sequence signal).
The signal was proposed by the David Sarnoff Research Center (DSRC) at the Stanford Institute. The GCR signal is inserted within the selected vertical blanking intervals (VBIs). In a television receiver, such a GCR signal is converted to an adjustable weighting factor (ad
The composite video signal, which is used to calculate justable weighting coefficients) but passes through the video detector, passes through a deghosting filter to provide a ghost suppressed response. The ghost removal filter adjusts the weight coefficient so as to be complementary to the characteristics of the transmission medium that generates the ghost. Also, the GCR signal is used to calculate the adjustable weighting factor of an equalization filter in series with the ghost removal filter, and to provide an essentially flat frequency response spectrum over the complete transmission path. used. This complete transmission path is based on the transmitter vestigial-side amplitude modulator.
band amplitude-modulator), a transmission medium, a television receiver front-end, a ghost elimination filter, and an equalization elimination filter connected in series with each other.

[0003] A conventional method for removing ghosts in a television receiver is to perform a discrete Fourier transform (DFT) of a ghosted GCR signal by using a DFT of a non-ghosted GCR signal (this is called a transmitter). It will be known by the receiver by prior consultation with)
, The DFT of the transmission medium that induces ghost is obtained in the form of minutes. The inverse DFT for this is used to define the filter weight coefficient of the ghost removal filter that compensates for the ghosted composite video signal. However, the ghosted composite video signal passes through the ghost removal filter and becomes a ghost-removed composite video signal. To effectively perform the DFT process in the calculations required by hardware or software,
The integral square of the two equalized bandwidth frequency values (bins) is DF
Used at T. The energy distribution in the Philips chirp signal has a frequency spectrum that is continuously extended across the composite video signal band. On the other hand, the energy distribution of the DSRC PN sequential signal, in contrast, exhibits a negligible (null) frequency distribution rather than being continuously extended across the composite video signal band. Therefore, when reducing the number of equalized bandwidth frequencies from the DFT in order to speed up the calculation time, the chirp of the GCR signal removes the ghost more accurately than the PN sequential signal.

While formally inspected by the Subcommittee, DSRC GCR signals have been ghosted and have shown better results in passband equalization, but this has been demonstrated by several people, including Philips engineers. Experts regard it as a result of better filter hardware. Theoretically, the accuracy of the equalization calculated over the active region of the VBI generated from the PN sequential signal is substantially equal to the accuracy of calculating and using the equalization from the chirp signal. The total length of the Philips chirp signal is required as information to perform equalization over the entire composite video signal band. The PN sequence signal includes pulse transitions, each of which has substantially all of the frequency spectrum contained therein. Although the PN sequence signal has many pulse transitions, each of the transitions has component frequencies that are spread over substantially the entire frequency spectrum. P
This property of the N-sequence signal allows an equalization calculation to sample at a given sampling density only over a limited range of the GCR signal. Taking samples only for a portion of the GCR signal introduces some loss in accuracy aspects when the equalization is calculated in a particularly low signal-to-noise state. However, the speed at which equalization is calculated because the number of samples involved in calculating the weighting coefficients for the equalization filter is reduced, assuming that the calculation is performed using an iterative method such as least mean square error reduction. Can be considerably faster. In addition, calculation of the equalization filter weight coefficient becomes simpler in calculation required by hardware or software.

[0005] The proposed composite GCR signal composed of a chirp signal and a PN sequential column signal does not use both the chirp signal and the PN sequential column signal during the same VBLI scan line.

[0006]

Accordingly, the present invention provides
By utilizing both the chirp signal and the PN sequence signal during the same VBLI scan line in each successive field, the ghost state changes quickly when the transmission medium changes continuously, for example, due to aircraft invasion. An object of the present invention is to provide a GCR signal capable of facilitating a faster and more efficient ghost removal calculation and equalization calculation since the ghost removal and the equalization process are performed continuously.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a television receiver which uses a chirp signal of a GCR signal and a PN signal based on a residual component of a composite video signal.
Means for sequentially separating portions of the column signal, ghost removal filters and equalization filters interconnected in series to respond to the composite video signal, each provided with an adjustable filter weight, Means for calculating a DFT in response to the separated chirp signal portion;
Means for determining an adjustable filter weight for the ghost removal filter in response to T; and means for determining an adjustable filter weight for the equalization filter in response to the separated PN sequence signal.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1A to 1D show a ghost elimination reference signal on a scanning line selected during a vertical cutoff period of four consecutive fields of a screen. The GCR signal can be inserted into any one of the 11th to 20th scanning lines of each field. Here, a vertical period reference (VIR: Vertical I) used for the 19th scanning line of each field is used.
nterval Reference) signal. As a special example for simplicity of the following description, assume that the GCR signal has been inserted into the 19th scan line of each field.

The ghost elimination reference signals shown in FIGS. 1A to 1D are horizontal synchronization pulses 11, 21, 31, 41, respectively.
And this pulse is falling (negative-going). The leading edge of the horizontal sync pulse is V
Considering the beginning of a BLI scan line, this VBLI scan line
Each of the TSC standard television signals has a period of 63.55 μs. Horizontal sync pulses 11, 21, 31, and 41
During the back porch period, color synchronization signals (color bursts) 12, 22, 32, and 42 are located. The +/- indications around the color sync signals 12, 22, 32, and 42 indicate the relative polarity of each color sync signal in the NTSC standard.

The Bessel pulse chirp signals 13, 23,
33 and 43 start from a 12 μs fulcrum and last for 33 μs during the VBLI scan line period of FIGS. The arrow displayed on each chirp signal indicates the relative polarity with respect to the other chirp signals, and the polarity of the chirp signal appears to be shifted between frames. This chirp signal oscillates +/- 40 IRE around a 30 IRE gray pedestal extended from a 12 μs fulcrum to a 48 μs fulcrum within the VBLI scan line period. The pedestal gray level, the +/- amplitude of the chirp signal, the period of the pedestal and the chirp signal are specified to code as close as possible to the officially tested Philips system, and the eclectic GCR signal referred to herein is a subdivision. Design variations to the extent that they can be officially recommended as standards by the committee are possible.

A PN consisting of 127 samples each
The sequential column signals 14, 24, 34, and 44 are shown in FIG.
(D) VBLI scanning line period starts from 51 μs fulcrum. The PN sequential column signals 14, 24, 34, and 44 are 9
lasts for μs. PN sequential column signal 14, 24, 3
In the last field of each frame, the PN sequence signal has the opposite polarity to the PN sequence signal of the first field of the frame, as indicated by the arrows displayed on each of 4, and 44, respectively. Has the same polarity as the PN sequence signal in the first field of the frame. This PN
The sequential column signals are -15 IRE and 95 IRE levels, respectively.
It has values of 1 and +1. This PN sequence signal is specified to match as closely as possible with the officially tested DSRC system and is referred to herein as the eclectic GCR.
Design variations are possible to the extent that the signal can be officially recommended as a standard by the subcommittee.

There is an opinion within the subcommittee that the duration of the Bessel pulse chirp signal must be reduced to 17 μs, which includes the GCR signal and the next V
Ghosts that have been delayed up to 40 μs can be removed, without the restriction that the BI scan line must not have information that changes between fields. if,
When the Bessel pulse chirp signal is shortened, the PN sequential sequence signal will have 22 of its length rather than 127 samples.
Must consist of 5 samples. here,
The compromised GCR signal can be adjusted by appropriate adjustment of the gray pedestal so that the oscillation width of the Bessel pulse chirp signal and the PN sequential column signal correspond. The present invention increases the amplitude of the chirp signal to be extended over the -15 IRE and 95 IRE ranges, and presents the gray pedestal to be set at 40 IRE. A chirp signal of reduced range was selected by Philips engineers to prevent over-vibration under any conditions, but the inventor prescribed that an automatic gain controller (AGC), an intermediate frequency amplifier, would pre-block such over-vibration. I'm sure you can. P
Extending the gray pedestal to the beginning of an N-sequence signal can be used for automatic gain control of a composite video signal when the signal passes through a low-pass filter and is substantially cut off in the middle of the scan line Provides 40 IRE level signals.

FIG. 2 shows that when differentially combining GCR signals from two consecutive fields in two consecutive frames,
The resulting separated Bessel pulse chirp signal waveform, where the GCR signal is assumed to be of the type shown in FIGS. 1 (A)-(D).
Further, F ₁ to F ₄ in FIG. 2 shows a GCR signal shown in each Figure 1 (A) ~ (D) . The waveforms of the separated Bessel pulse chirp signal shown in FIG. 2 are the same as those shown in FIGS.
This occurs when the R signals are differentially coupled or the GCR signals of FIGS. 1D and 1A are differentially coupled. Also, when the sum of the GCR signals of FIGS. 1A and 1B and the sum of the GCR signals of FIGS. 1C and 1D are differentially combined, the result also occurs.

FIG. 3 is a diagram showing the separation generated when the sum of the GCR signals of FIGS. 1A and 1D and the sum of the GCR signals of FIGS. 1B and 1C are differentially combined. FIG. 7 is a waveform diagram of a PN sequential column signal. F ₁ to F ₄ in FIG even again in FIG. 1 (A)
7 shows GCR signals shown in FIGS. The Bessel pulse chirp signal waveform, gray pedestal, and color synchronization signal are suppressed by this signal, and DC information related to 0IRE is lost. The PN sequence signal is maintained as a separated PN sequence signal.

FIG. 4 is a schematic block diagram of a television transmitter for an NTSC color television signal into which the GCR signals of FIGS. 1A to 1D are inserted. The processing amplifier 50 generates a composite video signal formed from the color video signal and the synchronization signal. For example, the color video signal can be a red, green, and blue signal generated by a studio color camera, and the synchronization signal is a studio signal. It can be a signal originating from a sync signal generator, but this sync signal also provides a sync signal to the studio color camera. Optionally,
The color video signal may be transmitted from a long distance, and the synchronization signal may be provided by a genlock connection. Or, if the local transmitter is a low power transmitter that relays a signal received as a broadcast from a long distance high power transmitter, the color video signal is generated by demodulating the received composite video signal, The synchronization signal is generated by demodulating the received composite video signal,
The synchronization signal can be separated from the received composite video signal.

The processing amplifier 50 has a color carrier frequency f
A crystal oscillator 51 vibrating eight times _C , a counter 52 for calculating the number of oscillations per horizontal scanning line, a counter 53 for calculating scanning lines per field,
Modular 4 (modulo-
4) A counter 54 for counting is provided. Processing amplifier 50 provides its composite video output signal as a first input signal of analog select switch 55. The output signal of the analog selection switch 55 is input to the video modulator 56 to control the residual sideband amplitude modulation of the video carrier signal, and the audio signal is input to the frequency modulator 57. The modulated video and audio carrier signals are amplified by RF amplifiers 58 and 59, respectively, and then combined by a combining circuit 60 to be broadcast through an antenna 61. Some variation in the conventional arrangements of television transmitters mentioned so far is a fact of television transmitter design which is well known in the art.

The analog select switch 55 is similar to the conventional one for inserting a vertical period reference (VIR) signal. The decoder 62 generates a logic signal "1" by detecting a counting portion related to the active area of the horizontal scanning line generated by the counter 52, that is, a horizontal scanning line portion excluding the horizontal cutoff period. The code decoder 63 responds to the scanning line count value generated by the counter 53 to decode whether or not the 19th scanning line is generated from each field, and then generate a logic signal "1". And AN
The D-gate 64 selects the second input signal among the two inputs of the analog selection switch 55 and applies the selected signal to the video modulator 56 in response to the inputs becoming the logic signal “1” at the same time. Here, the first input signal of the analog selection switch 55 is a composite video signal provided from the processing amplifier 50, and the second input signal is a continuous field which is not a VIR signal and is a continuous field shown in FIGS.
(D) or the continuous G shown in (A) to (D) of FIG.
This is one of the CR signals.

The GCR signal is stored in the ROM 65 in a discretized form. The first part of the address for ROM 65 is provided from counter 54, and the provided modulo 4 field count selects one of the GCR signals shown in FIGS. The GCR signal is inserted into the current field. The second part of the address for ROM 65 is provided by counter 52,
A selected one of the GCR signals shown in FIGS. 1A to 1D is scanned. The discretized GCR signal read from the ROM 65 is applied to a digital / analog converter 66. The resulting analog GCR signal is applied at the second input of the analog select switch 55 and inserted into the active area of the 19th scan line in the field.

FIG. 5 shows the GC shown in FIGS.
1 shows a television receiver for receiving a television signal including an R signal. The television signal received by the antenna 70 is amplified by the RF amplifier 71,
The converter 72 down-converts the signal to an intermediate frequency. The intermediate frequency amplifier 73 amplifies the intermediate frequency signal generated by the converter 72 and applies the amplified signal to the video sensor 74 and the audio sensor 75. The voice sensor 75 demodulates the frequency-modulated voice carrier and applies the result of voice detection to the audio device 76. Audio device 76, which may also include a stereo sound sensing circuit, includes an amplifier to provide amplified sound signals to loudspeakers 77 and 78.

An image sensor 74 converts an analog composite image signal into an analog / digital converter, a color synchronizing signal sensor 80,
It is provided to a horizontal sync separator 81 and a vertical sync separator 82. The separated horizontal sync pulse generated by the horizontal sync separator 81 and the separated vertical sync pulse generated by the vertical sync separator 82 are applied to a kinescope deflection circuit 83. Generates a deflection signal for The color synchronization gate generator 85 generates a color synchronization gate signal at an appropriate period after each horizontal synchronization pulse provided from the horizontal synchronization separator 81. The color synchronization gate signal controls the operation of the color synchronization signal detector 80 during the color synchronization signal. The color synchronization signal detector 80 is included in a phase locked loop for a phase locked oscillator (PLO) 86. The phase locked oscillator 86 oscillates at a sufficiently high frequency that the analog / digital converter 79, which samples the analog composite video signal provided from the video signal sensor 74 once for each oscillation, oversamples the signal. . As is well known, from the point of view of simple digital hardware design, it is convenient for the phase locked oscillator 86 to oscillate at a frequency that is a factor of 2 times the 3.58 MHz color subcarrier frequency. It is desirable to sample the chromaticity signal in the fourth to eighth positions per cycle.

The horizontal sync pulse separated from the horizontal sync separator 81 is applied to a scanning line counter 87 and counted. The scanning line count value counted by the counter 87 is separated from the vertical sync separator 82. The reset signal is reset to 0 at the start of each vertical synchronization cycle by the vertical synchronization pulse. From the counts provided by scan line counter 87, 19
The second scan line occurrence indication is sensed by the decoder 88. From the count provided by the counter 87, the occurrence of the 20th scan line in each field is detected by the decoder 89. The generation of the nineteenth and twentieth scan lines in each field is signaled to a GCR signal capture processor 90, which processes each of the digitized composite video signals generated by the analog to digital converter 79. Capture the GCR signal from the 19th scan line of the field. Such a capture process will be described in more detail in connection with FIG.

The GCR signal capture processor 90 includes circuitry for separating the Bessel pulse chirp signal portion from the captured GCR signal, which is applied to a deghost filter weight computer 91. The GCR signal capture processor 90 also includes circuitry for separating the PN sequential column signal portion from the captured GCR signal, which is applied to an equalization filter weight computer 92. The digitized composite video signal provided from the analog / digital converter 79 passes through a ghost removal filter 93 and an equalization filter 94 which are connected in series, and outputs a luminance / chromaticity separator 9.
5 is applied. The deghost filter 93 has adjustable filtering weights corresponding to the results calculated by the deghost filter weight computer 91. The equalization filter 94 also has adjustable filtering weights corresponding to the results of the calculation by the equalization filter weight computer 92.

The ghost removal filter weight computer 91 preferably divides the DFT of the ghosted GCR signal into the DFT of the non-ghosted GCR signal and takes the form of a DFT transform of the transmission medium that generates the ghost. This inverse DFT is used to define the filter weight coefficient of the compensation ghost removal filter. As is well known to those skilled in the ghost removal technique, the ghost removal filter 93 has a transparent center (sparse
Suitably, it has the form of a kernel), where the position assignments for the non-zero filter weights are shifted according to the result of the deghosting filter weight computer 91. Deghosting filters with dense kernels typically require 2048 filter weights, but are difficult to construct in nature.

Preferably, the equalization filter weight computer 92 performs the calculation using DFT, and the result is inverse DFT to define the filter weight coefficients of the compensation equalization filter 94. However, the equalization filter weight computer 92 performs a digital FIR filter used as a 15 tap iterative adjustment or equalization filter 94. It is desirable to have a configuration that uses the minimum mean square error, and the adjustment is performed in such a manner that the correlation result between the ghost-suppressed PN sequence signal portion and the corresponding PN sequence signal portion recognized as standard by the receiver is obtained. This is done to best match the sin x / x function.

The luminance / chrominance separator 95 suitably uses a digital comb filter to separate the digital luminance signal and the digital chrominance signal from each other. 96 and a digital chromaticity processor 97, respectively. The digital luminance (Y) signal generated by the digital luminance processor 96 and the I signal and the Q signal generated by the digital chromaticity processor 97 are supplied to a digital color matrix circuit 98. The digital color matrix circuit 98 receives the digital Y, I, and Q signals and converts the digital red, green, and blue signals into respective digital / analog converters 99, 100, and 1.
01. Digital / analog converter 99,1
The analog red, green, and blue signals generated through 00 and 101 are respectively applied to the red, green, and blue kinescope driving amplifiers 102 and 10.
3,104. The red, green, and blue kinescope drive amplifiers 102, 103, and 104 provide red, green, and blue drive signals to the kinescope 84.

Although the filter 94 described above has been referred to as an equalizing filter and providing a flat frequency response over the band, it is customary for this filter to be characterized by other technicians in ghost rejection techniques. . It is appropriate to adjust the filter weights to provide a frequency response that provides some temporary overshooting or undershooting or video peaking without effectively having a flat frequency response across the band from the filter 94. This reduces the need to provide temporary overshooting or video peaking in the digital luminance processor 96.

FIG. 6 is an exemplary method of constructing the GCR signal capture processor 90. RAM 111, 112,
Reference numerals 113 and 114 denote fields 00, 01 and 1 having the respective periods of four continuous fields of the digital composite video signal.
The GCR reference signal provided between 0 and 11 is arranged for line store. GCR like this
The reference signal is sent from the analog / digital converter 79 to the RAM.
(111, 112, 113, 114) are applied to the input side. In each cycle, four consecutive fields are counted by a two-stage binary counter 115 in a modulo-4 manner,
The two-stage binary counter 115 senses the display of the last scan line from one field provided by the scan line count provided by the counter 87. As a preliminary measure of the process of recentizing the filter weighting coefficients of the ghost removal filter 93, the appropriate step-by-step introduction of the modulo four-field count is determined by correlation seeking the best match. Is performed on the most recently received ghost-suppressed GCR signal and each of the four standard GCR signals stored in the receiver. The decoders 121, 122, 123, and 124 have one most significant bit provided by the nineteenth scan line decoder 88,
100, 10 composed of the two least significant bits provided by the field counter of field counter 115
Decode the 1,110,111 signals. As a result, the decoders 121, 12 between the 19th scan line of the continuous field
2, 123, and 124 write the write enable signal to RAM1
11, 112, 113, and 114 are sequentially provided.

RAMs 111, 112, 113 and 114 are address counters 1 for counting the number of samples per scanning line.
25 designates addresses in parallel. Address counter 125 receives the oscillation from phase locked oscillator 86 at the count input and is reset by the edge of the horizontal sync pulse. Such an addressing scan during the nineteenth scan line is performed in a position where continuous addressing can be performed from one of the RAMs 111, 112, 113, and 114 that receives the write enable signal. Assign each successive digital composite video signal sample.
During the 20th scan line, the decoder 89 is connected to the RAM 111,1.
A read enable signal is provided to all of 12, 13, and 114. During the 20th scan line, the counter 125 scans the addressed scans in the RAMs 111, 112, 11
3, the four most recent GCR signals received and stored in parallel are sent to the serial processor 126 to be combined with and separated from the sequential samples of the separated Bessel pulse chirp signal. Then, a sequential sample of the generated PN sequence signal is generated.

During the twentieth scan line, the decoder 89 also provides a write enable signal to the RAM 127 and RAM 128
The RAM 127 and the RAM 128 perform line storage for the separated chirp signal and the separated PN sequential column signal, respectively. Decryptor 89 allows address multiplexers 129 and 130 to select the address provided from address counter 125 while R
The address designation is written to each of the AM 127 and the RAM 128. Counter 125 provides the necessary addressing scans to RAM 127 to write sequential samples of the chirp signal separated from serial processor 126. Also, the counter 125 is provided with the separated PN generated from the serial processor 126.
An addressing scan is provided to RAM 128 for writing sequential samples of the sequential column signal. When different from the twentieth scan line, the address multiplexer 129 selects the RAM 127 to read the addressing provided by the deghost filter weight computer 91 during a data fetch operation, during which the computer 91 reads. The enable signal is applied to the RAM 127. When different from the twentieth scan line, address multiplexer 130 selects RAM 128 to read the addressing provided from equalization filter weights computer 92 during a data fetch operation, during which computer 92 Read enable signal to RAM
128.

FIGS. 7A to 7D show FIGS. 1A to 1D.
As another embodiment which can be substituted for the embodiment of (D), a waveform of a GCR signal in a vertical cutoff period selected in four continuous fields of a video signal is shown. The GCR signals in FIGS. 7A and 7D are the same as the signals in FIGS. 1A and 1D. The GCR signals in FIGS. 7B and 7C are different from the signals in FIGS. 1B and 1C in that the vibration directions of the PN sequential columns are opposite. From (B) and (C) in FIG.
The vibrations of the N sequential rows 24 'and 34' are in the same direction as the vibrations of the PN sequential rows 14 'and 44' of FIGS. 7A and 7D.

FIG. 8 shows the waveform of the separated Bessel pulse chirp signal. This is based on the assumption that the GCR signal is a GCR signal of the kind shown in FIGS. 7A to 7D. As a result, when differentially combining GCR signals from two consecutive fields in two consecutive frames. Here, F _{1 to} F ₄ indicate the GCR signals shown in FIGS. 7A to 7D, respectively. The waveform of the separated Bessel pulse chirp signal for FIG. 8 is shown in FIG.
7 (B) and 7 (C) are differentially combined, or the GCR signals of FIGS. 7 (A) and 7 (D) are differentially combined. Further, the waveform of the separated Bessel pulse chirp signal shown in FIG. 8 is obtained by differentially calculating the sum of the GCR signals of FIGS. 7A and 7B and the sum of the GCR signals of FIGS. 7C and 7D. Occurs as a result of static coupling.

FIG. 9 shows the waveform of the PN sequence signal generated when the GCR signals of the continuous fields of 4 or a predetermined multiple of 4 are additionally combined or averaged. Is assumed to be a signal of the type shown in FIGS. Also, F ₁ to F ₁ in FIG.
F ₄ shows the GCR signal in the respective Figure 7 (A) ~ (D) . The waveform of the Bessel pulse chirp signal and the color synchronization signal are suppressed by this signal. D with PN sequential column signal
The C level and the gray pedestal are also maintained with this signal. Thereafter, the PN sequence signals can be separated by a high-pass digital filter. The DC level and the gray pedestal can be separated by a low pass digital filter. DC levels and gray pedestals are useful in circuits that control gain or control the DC offset of an analog composite signal applied to analog to digital converter 79. This circuit was known from the prior art, but A
The output signal of the / D converter is selected as an input to a first digital comparator during a digitized composite video signal portion, commonly known as the 0IRE level, where the idealized 0IRE is digitized. 1st compared to the level
Generate a digital error signal. This first digital error signal is converted into an analog error signal by a digital / analog converter, and then fed back to reduce an error from the 0IRE level which hinders DC restoration of an input signal input to the analog / digital converter. . At a particular point in the circuit, the digital output signal of the same analog-to-digital converter will generally be at a predetermined pedestal level during a portion of the digitized composite video signal which is known to be at a predetermined pedestal level. A second digital error signal is generated which is selected as an input signal and which is compared in digital form with a predetermined pedestal level. This is converted to an analog error by the digital / analog converter and fed back to the gain adjustment amplifier as an automatic gain adjustment signal. The gain adjustment amplifier is located before the analog / digital converter and is connected to the analog / digital converter. Ensure that the input signal is perfectly accurate within the boundaries of the range of change.

FIG. 10 shows the configuration of the serial processor of FIG. 6 for processing the GCR signals of FIGS. 1A to 1D to generate the signals of FIGS. 2 and 3. The serial adder 131 adds the output of the RAM 111 for the signal of FIG. 1A and the output of the RAM 112 for the signal of FIG. The serial adder 132 adds the output of the RAM 113 for the signal of FIG. 1C and the output of the RAM 114 for the signal of FIG. Serial subtractor 13
3 generates a separated Bessel pulse chirp signal by subtracting the sum output of the adder 132 from the sum output of the adder 131. Shifting two less significant bits to the less significant bit to accomplish the task of dividing by 4 in parentheses in FIG. 2 results in the separated Bessel pulse chirp signal of FIG. The serial adder 134 adds the output of the RAM 112 for the signal of FIG. 1D and the output signal of the RAM 113 for the signal of FIG. The serial subtractor 136 subtracts the sum output of the adder 135 from the sum output of the adder 134 to generate a separated PN sequence signal. 2 towards the less important bits to perform the divide by 4 operation shown in parentheses in FIG.
After shifting by a digit, the separated PN sequence signal shown in FIG. 3 is obtained.

FIG. 11 shows the configuration of the serial processor shown in FIG. 6 which processes the GCR signals shown in FIGS. 7A to 7D to generate the signals shown in FIGS. Serial adders 131 and 132 and serial subtractor 133 interact to generate a separate Bessel pulse chirp signal as described in connection with FIG. Shifting two less significant bits to the less significant bit to perform the divide by 4 operation shown in parentheses in FIG. 8 results in the separated Bessel pulse chirp signal of FIG. Serial adder 137 adds the outputs of the sums to adders 131 and 132 to generate a separated PN sequence signal. A two digit shift to less significant bits to accomplish the divide by four operation shown in parentheses in FIG. 9 results in the separated PN sequential signal of FIG.

[0035]

Those skilled in the art of electronic circuit and system design, and those familiar with the above-described invention, may make slight changes in the design within the scope of the appended claims of the signals and circuits disclosed in the embodiments. There is an effect that can be made.

[Brief description of the drawings]

FIG. 1 is a waveform diagram of a ghost removal reference signal in a selected vertical cutoff period of four continuous fields of a video signal according to an embodiment of the present invention.

FIG. 2 is a diagram showing a separation formed by differentially combining the sum of the ghost removal reference signals of FIGS. 1A and 1B and the sum of the ghost removal reference signals of FIGS. 1C and 1D. FIG. 7 is a waveform diagram of a chirp signal obtained.

FIG. 3 is a diagram showing a separation formed by differentially combining the sum of the ghost removal reference signals of FIGS. 1A and 1D and the sum of the ghost removal reference signals of FIGS. 1B and 1C. FIG. 7 is a waveform diagram of a PN sequential column signal obtained.

FIG. 4 is a schematic diagram of a television modulator for transmitting the signals of FIGS. 1A to 1D.

FIG. 5: To suppress ghosts associated with television signals and equalize transmission channels across the bandwidth of video signals,
FIG. 2 is a schematic diagram of a television receiver that receives a television signal including the ghost removal reference signal of FIGS. 1A to 1D.

FIG. 6 is a schematic diagram of a ghost elimination reference signal capture processor shown in the block of FIG. 5;

FIG. 7 is a waveform diagram of a ghost removal reference signal in a selected vertical cutoff period of four continuous fields of a video signal according to another embodiment of the present invention.

8 (B) and FIG. 7 (C) are combined with the ghost removal reference signal, FIG. 7 (D) and FIG. 7 (A) are combined with the ghost removal reference signal, or FIG. FIG. 7 is a waveform diagram of a separated chirp signal formed by combining the ghost removal reference signals of (A) to (D).

9 is a waveform diagram of a separated PN sequence formed by combining the ghost removal reference signals of FIGS. 7A to 7D and preceded by a gray pedestal.

FIG. 10 is a schematic diagram of a serial processor that processes the ghost removal reference signals of FIGS. 1A-1D to generate the signals of FIGS. 2 and 3;

FIG. 11 processes the ghost elimination reference signals of FIGS. 7A to 7D to generate the signals of FIGS. 8 and 9;
FIG. 2 is a schematic diagram of a serial processor.

[Explanation of symbols]

11, 21, 31, 41 Horizontal synchronization pulse 12, 22, 32, 42 Color burst 13, 23, 33, 43 Chirp signal 14, 24, 34, 44 Pseudo noise sequential column signal 50 Processing amplifier 51 Crystal oscillator 52, 53, 54 counter 55 analog selection switch 56 video modulator 57 frequency modulator 58, 59, 71 RF amplifier 60 coupling circuit 61, 70 antenna 62, 88, 89, 121, 122, 123, 124
Decoder 63 Code decoder 64 AND gate 65 ROM 66,99,100,101 Digital / analog converter 72 Converter 73 Intermediate frequency amplifier 74 Video sensor 75 Audio sensor 76 Audio device 77,78 Loudspeaker 80 Color synchronization signal Sensor 81 Horizontal sync separator 82 Vertical sync separator 83 Kinescope deflection circuit 84 Kinescope 85 Color sync gate generator 86 Phase locked oscillator 87 Counter 90 GCR signal capture processor 91 Ghost removal filter weight computer 92 Equalization filter weight Value computer 93 Ghost removal filter 94 Equalization filter 95 Luminance / chrominance separator 96 Digital luminance processor 97 Digital chrominance processor 98 Digital color matrix circuit 102, 103, 104 Blue kinetics Coop driving amplifier 111,112,113,114,127,128 R
AM 115 2-stage binary counter 125 Address counter 126 Serial processor 129, 130 Address multiplexer 131, 132, 134, 137 Serial adder 133, 136 Serial subtractor

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-265867 (JP, A) JP-A-1-240093 (JP, A) JP-A-1-209882 (JP, A)

Claims (26)

(57) [Claims] 1. A ghost canceling method using a ghost canceling reference signal included in the composite video signal, said ghost canceling reference signal, the activity of <br/> single scan line in each vertical blanking interval It includes both chirp signals and a pseudo-noise sequence column signal in the area, the said chirp signal in the single in one scan line during each vertical blanking period, wherein the Turkey be preceded noise sequential series signals similar該擬Ghost removal method. Wherein the chirp signal portion and said pseudo noise sequence column signal portion of said ghost canceling reference signal of the composite video signal, the composite video signal of the chirp signal portion and the upper
Means for separating from portions other than the pseudo-noise sequential signal; a ghost removal filter provided with an adjustable filtering weight; and an adjustable filtering connected in series with the ghost removal filter to respond to a composite video signal an equalization filter that weights are provided, means for calculating a de office cleat Fourier transform in response to the pseudo-noise sequence column signal portion of the separated ghost canceling reference signal in response to the discrete Fourier transform means for determining an adjustable filtering weights deghosting filter, a television receiver and means for determining the adjustable filtering weights of the equalization filter in response to said separated pseudo-noise sequence column signal And the Bessel pulse timing is applied to the selected scan line during the vertical blanking period of each field. The-loop signal and a pseudo-noise sequence column signal
A television receiver using a ghost cancellation reference signal (GCR) in a form that includes both . 3. A ghost elimination method using a ghost elimination reference signal included in a composite video signal, wherein the ghost elimination reference signal is selected from the composite video signal.
Includes both-option chirp signals and a pseudo-noise sequence column signal in the active region of the scanning lines of each field, the chirp signal in a scan line of each field is 該選-option prior to the noise sequential series signals similar該擬ghost removal method according to claim and to Turkey. 4. Each file selected from the composite video signal.
Rudo includes pairs of successive fields, the scanning of one field of each said pair of successive fields
Line deghosting reference signal and the corresponding other field
Ghost canceling reference signal de scanline, mutually same direction
Of having a switch chirp signal, the said one field of each said pair of successive fields
The scan line ghost removal reference signal and the corresponding other
The ghost removal reference signals of the field scan lines are
Ghost canceling method of claim 3, wherein the benzalkonium which have a pseudo-noise sequence column signal in the opposite direction. 5. The said one of each pair of said sequential fields.
Ghost removal reference signal of the scanning line of the field of
Ghost removal criterion for corresponding other field scan line
Signal is ghost canceling method according to claim 4, wherein the benzalkonium that have a color burst of opposite directions. 6. Both of the preceding sequential field pairs
The ghost removal reference signal of the scanning line of the field and the above
Sequential field following a sequential pair of fields to be lined
Ghost removal of scan lines in both fields in a field pair
The reference signal is a ghost canceling method of claim 5, wherein the Turkey of having a switch chirp signal in the opposite direction. 7. A method according to claim 1 , wherein each pair of said sequential fields includes both flags.
Scan line of the field is, ghost canceling method according to claim 4, wherein the Turkey occur during the vertical blanking interval of the composite video signal. 8. The method of claim 1 , wherein both pairs of each of said sequential fields are associated with each other.
Scan line of the field is, ghost canceling method of claim 7 wherein the benzalkonium occur successive fields during the vertical blanking interval of the composite video signal. 9. The said one of each pair of said sequential fields.
Ghost removal reference signal of the scanning line of the field of
Ghost removal criterion for corresponding other field scan line
Signal is a ghost canceling method of claim 7 wherein the benzalkonium that have a color burst of opposite directions. 10. Both preceding preceding pairs of fields.
Ghost removal reference signal of the scanning line of the field of
Sequential fees following the pair of successive fields preceding
Ghost removal of scan lines in both fields in a field pair
Removed by the reference signal is a ghost canceling method of claim 9, wherein the Turkey of having a switch chirp signal in the opposite direction. 11. Both preceding preceding field pairs.
Ghost removal reference signal of the scanning line of the field of
A sequential field that follows a preceding pair of sequential fields
Ghost removal of scan lines in both fields in a field pair
Removed by the reference signal is a ghost canceling method of claim 8, wherein the Turkey of having a switch chirp signal in the opposite direction. 12. A means responsive to a television signal to provide the composite video signal ; and a chirp portion of a ghost elimination reference (GCR) signal of the composite video signal.
To separate the components other than chirp portion, the composite
Scanning of four sequential fields selected from the video signal
Lines F1, F2, F3, and F4 are represented by (F1 + F2)-(F3
+ F4) and means for coupling in the form of; the composite pseudo-noise GCR signal of the video signal (PN) sequence string part a pseudo-noise of the GCR signal of the composite video signal (PN)
To separate the components other than sequential series portion, the composite image
Scan lines F of four sequential fields selected from the signal
1, F2, F3, and F4 are calculated as (F1 + F4)-(F2 + F
Means for combining in the form of 3) ; a deghosting filter; an equalizing filter cascaded to respond to the composite video signal, each providing an adjustable filter weight; and a separated chirp portion of the GCR signal. Means for calculating a discrete Fourier transform (DFT) therefrom; means for responsive to the DFT and for determining an adjustable filter weight of the deghosting filter; and responsive to the separated PN sequential signal; 12. A television receiver using a ghost elimination reference signal according to claim 11, comprising means for determining an adjustable filter weight of the equalization filter. 13. A rubber paste removal method using a ghost canceling reference signal included in the composite video signal, it said ghost canceling reference signal is selected from the composite video signal
Includes the-option activity region of the scanning lines of each field both chirp signals and a pseudo-noise sequence column signals, each full predetermined scanning lines of the vertical blanking period that is the selected
Ghost canceling wherein the Turkey be corresponding to the scanning line of the field. Within 14. The scanning lines of each field are 該選-option, the chirp signal precedes noise sequential series similar該擬, each successive field selected from said composite video signal
Ghost removal reference signal for the scan line of one field of the pair
And the corresponding other field scan line ghost removal
Reference signal has a mutually Ji chirp signal in the same direction, the scanning of one field of each said pair of successive fields
Line deghosting reference signal and the corresponding other field
The ghost removal reference signals of the scanning lines of
Claim, characterized in a Turkey which have a pseudo-noise sequence column signal 1
3. The ghost removal method according to 3. 15. One of each pair of said sequential fields.
The ghost removal reference signal of the scanning line of the field and the corresponding
Ghost removal reference signal for the scan line of the other field
The ghost canceling method of claim 14, wherein the benzalkonium that have a color burst of opposite directions. 16. Both preceding preceding field pairs.
Ghost removal reference signal of the scanning line of the field of
A sequential field that follows a preceding pair of sequential fields
Ghost removal of scan lines in both fields in a field pair
Removed by the reference signal is a ghost canceling method of claim 15, wherein the benzalkonium which having a switch chirp signal in the opposite direction. 17. A ghost elimination method using a ghost elimination reference signal included in a composite video signal, wherein the ghost elimination reference signal is selected from the composite video signal.
Each of the sequential fields selected from the composite video signal includes both a chirp signal and a pseudo-noise sequential signal in the active area of the scanning line of each selected field.
Ghost removal reference signal at the scanning edge of one field of the pair
If, ghost removal of the corresponding other field scan line
Reference signal has a mutually pseudo noise sequence No. multiple message in the same direction, of said one field of each said pair of successive fields
The scan line ghost removal reference signal and the corresponding other
Ghost canceling reference signal of the scanning lines of the field, ghost canceling wherein the Turkey of having a chirp signal in the opposite direction to each other. 18. A ghost removal criterion ( G) for a composite video signal.
The chirp and pseudo-noise ( PN ) sequence part of the CR ) signal are converted into the chirp and PN sequence of the GCR signal of the composite video signal
Said means for separating from the components other than the column portion; means and a scanning line for selecting from the vertical blanking interval of each field having the GCR signal; chirp portion of the GCR signal, the chirp GCR signals of the composite video signal To separate from other components ,
Of four sequential fields selected from the composite video signal
Scan lines F1, F2, F3, and F4 are represented by (F1 + F2)-
Means for combining in the form of (F3 + F4) ; a pseudo-noise (PN) sequential column portion of the GCR signal, and a pseudo-noise (PN) sequential column portion of the GCR signal of the composite video signal.
Selected from the above composite video signal to separate it from other components.
The scanning lines F1, F2, of the selected four sequential fields
3. The television receiver according to claim 2, further comprising: means for combining F3 and F4 in the form of (F1 + F4 + F2 + F3) . 19. The method according to claim 19, further comprising the steps of: performing a scan from a sequential field , including a single chirp having a pedestal and a pseudo-noise signal on a selected scan line within a vertical blanking interval of each field.
First and second orientation of the chirp predetermined pattern of査線
And the chirp in the scan line is of a type preceding the pseudo-noise sequence signal (GCR).
A television receiver for television signals including a signal, means and responsive to the television signal so as to supply a composite video signal; chirp information of the composite video signal, the of the composite video signal
Means for separating from components other than chirp information ; within a scanning line within a vertical blanking period of each field
Et al., Means for selecting an even number of scanning lines having a chirp, for generating samples of said chirp information without the pedestal, an even number of scanning lines which are the selected
Consider the direction of the chirp pattern included in the above scanning line
A ghost removal filter; and a means responsive to the separated chirp information to calculate an adjustable filter weight of the ghost removal filter. 20. In response to the separated chirp information,
Means for calculating the adjustable filter weights of the deghosting filter; responsive to the separated chirp portion of the GCR signal and then calculating a discrete Fourier transform (DFT); and responsive to the DFT and deghosting. Means for determining an adjustable filter weight of the filter.
The television receiver as described. 21. A television receiver as claimed in claim 20, wherein the number of the selected even number of scanning lines <br/> is 4. 22. A television receiver as claimed in claim 20, wherein the number of the selected even number of scanning lines <br/> is a multiple of 4. 23. A television receiver as claimed in claim 19, wherein the number of the selected even number of scanning lines <br/> is 4. 24. A television receiver as claimed in claim 19, wherein the number of the selected even number of scanning lines <br/> is a multiple of 4. 25. Means for separating information related to the pedestal of the chirp information, separated from the chirp information, the means comprising: within a scan line within a vertical blanking interval of each field.
Et al., And hand stage you select an even number of scanning lines having a chirp, it separated from the chirp information, to generate a sample of the information about the pedestal of the chirp information, on
The even number of the selected scanning lines is
20. The television receiver according to claim 19, further comprising: means for adding together taking into account the direction of the screen. 26. has a pedestal to the selected scanning line in the vertical blanking interval of each field, successive fields
Of the chirp of the scanning lines Jo Tokoro pattern from de first
And a single chirp that having a second orientation, and a pseudo-noise sequence column signals, said the chirp in the scanning line pseudo noise is a sequential type preceding the column signal ghost canceling reference (GCR) signal A television receiver for a television signal comprising: means for responding to the television signal to provide a composite video signal ; and means for separating information relating to the pedestal of the chirp information separated from the chirp information. The means for separating the information on the pedestal is provided in the scanning line within the vertical blanking period of each field.
Et al., And hand stage select an even number of scanning lines having a chirp, to generate a sample of the information about the pedestal of the chirp information separated from the chirp information, which is the <br/> selected The even number of scan lines is
Means that take into account the direction of the
Revision receiver.